You were beginning to note the register of his Teacher voice. This was familiar ground, untouched by magma. The ward undulated in the shadows a little, which was a trick of the light and the blood. You said, “It’s just a ghost ward,” and after a second regretted speaking like a provincial bone witch.

Thankfully Ianthe was even more petulant, and a dyed-in-the-wool flesh magician, as she added: “It’s not even a sophisticated ghost ward. I mean, it’s exquisite, impeccable right down to the coagulation. But I was doing those when I was five.”

“That ghost repellent will keep our ship from shaking apart,” said the Emperor. “That ghost repellent will have every lonesome spirit for kilometres screaming away. For a time.”

“One minute, thirty-three seconds,” said Mercy.

He said, “Give or take.”

The Emperor came to drop on his haunches in front of you and Ianthe, as he had squatted before Mercymorn earlier. It still hurt you in an undefinable way, to see him lowered so: as though he offered a compliance test where you ought to flatten yourself in front of him as low as you could go. The white ring around his pupil was so white. “Your job is simple in the way most very tough things are. I will push us into the River, and I’ll push the ship with us. You’ll have to keep your minds—I can take your physical bodies, but your souls won’t go with them, not without you holding them steady.”

“Physical transference past the liminal boundaries,” you said, and were surprised by the knowledge coming out of you, as though it weren’t your own. “This is deep Fifth spirit magic.”

“And I bless the Fifth House and I bless their long memory,” said the Emperor. “They only go far enough to tempt lost ghosts to them. They stand on the sidelines and wave around bits of meat and anchoring material. But they don’t even approach the shore.”

Ianthe sounded much more like her twin sister when she said, wonderingly: “But if applied universally, this would revolutionise the fleet. We could expend no fuel or effort, travelling instantly. We would be truly unstoppable.”

Mercy laughed a nasty trill of laughter. “A powerful necromancer at the peak of their game could last ten seconds in the River,” said God, pushing himself up to stand. “Soul magic is the great leveller. In the first few seconds their thanergy would all be stripped away … then their thalergy, and then their soul. They wouldn’t have time for the ghosts to get to them. They cannot, returning to our analogy, live in magma.”

“We can live in magma,” said Mercymorn, then pressed one elbow into the pilot’s deck and pressed her head into that elbow, and complained: “Now I’m doing it.”